What is the best way to clean the engine.
Thanks.

 

A good degreaser (I like Castrol Super Clean), a brush, and some effort. Spray the degreaser on full strength while keeping it away from the alternator and other accessories with bearings. Let it sit about 10 minutes. Then rinse clean with a hose. Now cut it to about 30% Super Clean/70% water. With a stiff bristle brush, scrub out all the hard areas. Rinse again. Repeat as many times as necessary. Start the engine to dry it off.

Now when you wash the car, all it should take is a spray bottle with water and dish soap to keep it clean.

 

I use plastic grocery bags with rubber bands over the relay and fuse boxes. Pressure wand with water only. Careful not to get too agressive/close around small hoses and solenoids. Compressed air if you have it to dry the blingy stuff and run the engine to dry everything else.